[W126 Coupe] tornado air twister

[eurotech1 at charter.net]

Hi Jim,

  In the case of a 318 BMW we turbo'd at the shop I worked at, we had to remap the fuel map in the ECU.We used a H-P laptop with a USB to diagnostic connector cord. We connected the connector to a piggyback computer on the BMW ECU. The piggyback overwrote the original fuel map with a program from Underdog Racing Development we used to remap.
We read the air/fuel ratio with a wideband sensor display unit from Innovate Motorsports. As you know, 14.7:1 is the ideal air/fuel ratio for a gasoline engine. At higher RPM at the top end of the boost (18 lbs.), we set the mixture at 14.3-14.5:1 (a hair richer) to prevent a lean condition at WOT. Tuning the fuel map made a world of difference, as a matter of fact, the brand new BMW clutch and pressure plate were starting to slip at about 3500 RPM , the motor was producing so much torque. A Centerforce six-puck racing clutch and pressure plate took care of that. The 1.8 had a pair of cams from Web-cam, Rossi 8.5:1 pistons, rods were stress-relieved, the turbo came from a 2.0 Buick Skyhawk, and used a Jackson Racing dump valve. Used Innovate's electronic boost control unit, with an indash control center. On a Dynojet dyno, it did 307 hp at 6200 rpm at 20 lbs. of boost, with a 50 shot of nitrous at 5800.
That was a fun car!

                       Later,
                       Chris
============================================================ 
> From: Jim Nowak <jjnowak_32503 at yahoo.com>
> Date: 2005/04/02 Sat PM 11:46:59 EST
> To: Mercedes Coupes Mailing Lists <mbcoupes at mbcoupes.com>
> Subject: RE: [W126 Coupe] tornado air twister
> 
> Eddie,
> 
> No, you need to adjust the EHA screw to get the needed
> fuel even in low boost applications. 
> 
> Jim
> 
> 
> --- Eddie <cyberdrakon at hotmail.com> wrote:
> > But doesn't the metering plate adjust fuel for the
> > increase in air? (up to a
> > certain point).
> > 
> > Eddie
> > 
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